walkins



(No Model.) L E WALKINS 3 SheetS-Sheetq 1. GEARING FOR GAR TRUCKS.

Patented Jafi. 5, 189 7,

Inventor.

W itnesses:

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Attorney.

L. E. WALKINS.

' GEARING FOR GAR TRUGKS.

No. 574,646. Patented Jan, 5, 1897. I

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W itnesses.

UNITED STATES PATENT OFFICE.

LOUIS E. XVALKINS, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO GEORGE H. DREW, TRUSTEE, OF SAME PLACE.

GEARING FOR CAR-TRUCKS.

SPECIFICATION-forming part of Letters Patent No. 574,646, dated January 5, 1897.

Application filed April 8, 1896. Serial No. 586,716. (No model.)

To all whom, it may concern.-

Be it known that I, LOUIS E. \VALKINS, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Gearing for Car- Trucks and Locomotives; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as to will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

The present invention relates to the class of railway cars or locomotives propelled by electric motors which have drive or sprocket chains for transmit-ting the power from the motor-shaft to the traction-wheels, and more particularly to those where frictional contact with the drive or sprocket chain is relied on to transmit the power to the traction-wheels instead of having sprockets or teeth on the driven wheel.

A sprocket-chain connection for transmitting power from the motor-shaft to the traction-wheels of a car or locomotive has many advantages over other systems that have been employed, for it is positive in its action, it is not easily clogged by dirt or dust, and a break can be easily repaired. It particularly admits of a positive connection with the small rapidly-revolving pulley of the motor, but where the driven wheel is a drum and not a 3 5 sprocket-wheel it is necessary to secure as large an arc of contact of the sprocket-chain with the drum as possible and to preserve sufficient tension on the drive-chain to keep it from slipping under its greatest load. To 0 this end it has heretofore been proposed to regulate the tension on the drive-chain by means of an adj ustable idler-pulley, the path of the'chain or cable around the motor-pulley, the drum or drums, and the idler-pulley all being in the same plane, and with the motorpulley and the idler, respectively, above and below a single contin uous drive chain or cable which passes around drums on a pair of carwheels or on wheel-axles; but this arrangement has not always given satisfactory results, and the object the present invention from being injured by any obstruction.

has in View is to secure better frictional contact for the drive chain or cable with the drum or pulley. This Isecure by crossing the drivechain between the drum and the motor-pulley and idler, so as to considerably increase the arc of contact between the drive chain or cable and the drum, as hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a side elevation, partly in section; and Fig. 2 is a plan view of so much of a car-truck as is necessary to illustrate the novel features of the invention. Figs. 3 and aillustrate in plan and side views, respectively, a spring-support for the idler-pulley; and Fig. 5 shows the same with adjustable bearings for the idler as well.

A A are the axles of a car-truck, a locomotiye, or other vehicle with the traction-wheels A A.

B indicates an electric motor hung between the axles and having on one or both ends of its armature-shaft a sprocket-wheel b. A portion of the car-truck frame is shown at O, from which the motor B is suspended, and O O are braces which may extend from the motor up to the truck-frame.

It will be understood that the character of the truck or other structure supported on the So traction-wheels is not material to the present case, and hence only so much of the frame is indicated as will show the relation that the motor bears to the traction-wheels.

Carried on the inner face of each traction- 8 5 wheel is a drum D, the diameter of this drum being somewhat less than that of the Wheels, so that the drive-chain is suliiciently removed from the vicinity of the track to prevent it The drum may, however, be an independent friction-wheel keyed to the axle instead of being cast on or attached to the car-wheel. The drums have flanges (Z to retain the drive-chain on the wheel, and they may be faced with 5 hard leather or rubber to increase and insure the grip of the chain.

On each side of the truck and above each of the driving-pulleys b, but offset outward with respect thereto, are vertically-adj ust- 1 o able idler-pulleys E, which may be sprocketwheels or flanged pulleys, and the sprocketchain F, on either side of the truck, passes around the drums D D of the respective traction-wheels on that side of the truck, with the intermediate stretches of the chain crossed. The upper stretch of drive-chain coming from the drums passes down under the driving pulley Z) of the motor, while the lower stretch of chain coming from the drums passes up over the idler E. It will be seen that this crossing of the chain between the central driving-pulley and idler and the driven wheel at either end increases the are of frictional con tact which the chain makes with each driven wheel over that which it has when the chain passes from the drum to the driving-pulley and idler without crossing, and thus the chain will drive under a heavy load without requiring excessive tension. To accommodate the crossing of the drive-chain, the idler-pulley is set outside of the vertical plane of the driving-pulley, as before stated, and hence the drive-chain, in passing to and from the driven wheels and the driving-pulley and idler, is laterally deflected with respect to a vertical plane, as clearly indicated in Fig. 2, so that it can cross without interfering.

Each idler-pulley E is supported by a hanger E, carried by the frame, and it is Vertically adjustable in its bearings by means of a screw 6 or other convenient mechanism, by means of which it can be raised to increase the ten sion on the drive-chain when required.

Referring to Figs. 3, 4, and 5, the idler-pulley is shown supported on springs S, In this case II is a bridge-piece carrying the idler E, v and the latter may be vertically adjustable with respect to the supporting bridge by means of the adjusting-screws e (shown in Fig. 5) or otherwise. The ends of the bridgepiece II slide vertically on posts h, carried by the truck-frame, and rest on the springs S, encircling the posts beneath the ends of the bridge.

hat I claim is- 1. In a railway-truck the combination of a pair of drums, an intermediate driving-pulley, and an adjustable idler-pulley, with a crossed drive-chain engaging with the drums, the driving-pulley, and the idler, as and for the purpose set forth;

2. In a railway-truck the combination of a pair of drums, an intermediate driving-pulley, and an adjustable spring-supported idlerpulley, with a crossed drive-chain engaging with the drums, the driving-pulley, and the idler, as and for the purpose set forth.

3. In a railway-truck the combination of a pair of axles carrying traction-wheels and drums, and a sprocket-chain passing around the same, with an intermediate sprocket driving-pulley, and an adjustable idler-pulley above it, the sprocket-chain passing from the top of the drums below the driving-pulley, and from the bottom of the drums above the idler, as and for the purpose set forth.

In testimony whereof I afiix my signature in presence of two witnesses.

LOUIS E. VVALKINS.

Witnesses:

P. B. CHENEY, E. M. DREW. 

